Electric plug and socket



Peb. 14, 1939. H R ELUS ELECTRIC PLUG AND SOCKET Filed April 26, 1957Patented Feb. 14, 1939 UNITED STATES PATENT OFFECE ELECTRIC PLUG ANDySOCKET Horace R. Ellis, Meadville, Pa.

Application April 26, 1937, Serial No. 139,043

12 Claims.

This invention relates to electrical connections and has specialreference to a plug and socket connection for connecting a two wireflexible cable to a pair of feed wires.

The ordinary connection of this character consists of a plug having apair of stii prongs xedly carried thereby and adapted to enter a sockethaving a pair of contacts fixed therein wherewith the prongs engage uponentering the socket. Such devices depend entirely upon friction to holdthem together. These frictionally held connections are peculiarly apt toseparate under the Stresses induced by pulls on the cable such as oftenoccur when the flexible cable is used for connecting such aninstrumentality as an electrically'heated iron to a house circuit sincethe user of the iron frequently tightens the flexible connection.

fected by flexing of the prongs.

A second important object of the invention is to provide socket means,in such a connection, whereby the prongs inserted therein are caused totake a sinuous path. l

A third important object of the invention is to provide a novelarrangement of this character which may be used with any existing socketfor a two-prong plug.

A fourth important object of the invention is to provide a novel socketattachment adapted to be secured over an ordinary two-prong socket andwhich will cause flexing of the prongs of a plug as they are inserted inthe socket.

With the above and other objects in View the invention consists ingeneral of certain novel details of construction and combinations ofparts hereinafter fully described, illustrated in the accompanyingdrawing and pointed out in the appended claims.

In the accompanying drawing like characters of reference indicate likeparts in the several views and Figure 1 is a front elevation of thedevice with its parts assembled.

Figure 2 is a section on the line 2--2 of Figure 1.

Figure 3 is a face view of the plug element of the device.

Figure 4 is a section on the line 4 4 of Fig ure 2. l

Figure 5 is a section on the line 5-5 of Figure 2. l

Figure 6 is a fragmentary View showing the face of the socket element ofthe device.

Figure 7 is a side elevation of the plug element of the inventiondisconnected from the socket.

In the embodiment of the invention as here shown the device includes aplug element id and a socket element il. The plug element consists of asemi-ovate body i2 of insulating material. In the front or face of thebody is a circular recess i3 from which extends an axial bore M havingan enlargement l5 opening into the recess i3. This provides a flatannular surface It. On this surface is seated a pair of arcuate prongbases Il which are xed in place by tubular rivets it molded into thebody i2. These bases il are disn posed diametrically opposite each otherand each carries a binding screw I9 adjacent one end so as to providemeans for connecting the two wires of a iiexible-cable. The remainingends of the bases l1 have a pair of parallel prongs 2t which are ofstandard width and spacing. These prongs are made of thin exible metalpreferably hav ing a considerable degree of resiliency. These prongs arestraight when disconnected from the socket l l as is shown in Figure 7.

The socket is preferably molded unitarily from a suitable insulatingmaterial such as a synthetic resin, Bakelite being a suitable materialfor the purpose. This socket consists of a base portion 2l having a boss22 projecting from its center. Through this socket extends a pair ofprong passages having aligned end portions 23 and outwardly bowedcentral portions Edi connected to the ends 23 by curved portions 25. Theouter end portions are provided with flaring mouths 2S. There is thusformed a pair of sinuous prong passages and these passages are spaced attheir ends to conform to the spacing of the prongs 2t and these prongsare of sufficient length to project far enough through the base ffii toenter a standard socket, indicated typically at El, and engage thecontacts 28 thereof. The base 2i is provided with screw-holes 29 for thereception of screws 30 engaging in wall 3i or the like soV that thesocket Ii can be secured over the socket 2l with the prong passages Z2,23, 241 in registry with the openings of said socket 2l.

It will be plain from Figure 2 that the insertion of the prongs in thesinuous passages causes the flexible prongs to assume a sinuous shapefor portions of their length, this being effected against the tendencyof the prongs to remain straight.` The resiliency of the prongs causesthem to bind in the passages and thus the plug is held very securely tothe socket Il and Will not become accidently disengaged.

What is claimed is:

1. In a connector for electric Wiring, a plug body having a plurality ofvprongs extending therefrom each consisting of a thin strip of readilyfiexible material, socket means having a plurality of prong passages forreceiving said prongs, said passages having aligned end terminalportions and offset intermediate portions to cause the flexing of theprongs intermediate their ends when inserted into said passages, saidpassages extending entirely through said socket means and the prongsbeing of sufiicient length to project beyond the socket means to enter astandard socket, and means for securing said socket means on a standardsocket With said passages registering with the prong openings of thestandard socket.

2. In a connector for electric wiring, a plug body having a plurality ofnormally straight prongs projecting therefrom, said prongs eachconsisting of a thin strip of readily flexible conductive material,socket means having a plurality of prong passages for receiving saidprongs, said passages having endwise aligned end terminal portions andoffset intermediate portions to cause the flexing of the prongsintermediate their ends when the prongs are inserted into the passages,the offset intermediate portions of the passage being disposed inoppositely extending relation, said passages extending entirely throughsaid socket means and the prongs being of sufiicient length to projectbeyond the socket means to enter a standard socket, and means forsecuring said socket means on a standard socket with said passagesregistering with the prong openings of the standard socket.

3. In a connector for electric wiring, a plug body having a plurality ofnormally straight prongs projecting therefrom, said prongs eachconsisting of a thin strip of readily exible conductive material, socketmeans having a plurality of sinuous prong passages for receiving saidprongs, said passages extending entirely through said socket means andthe prongs being of sufficient length to project beyond the socket meansto enter a standard socket, and means for securing said socket means ona standard socket with said passages registering with the prong openingsof the standard socket.

4. In a connector for electric wiring, a plug body having a plurality ofnormally straight prongs projecting therefrom, said prongs eachconsisting of a thin strip of readily exible conductive material, socketmeans having a plurality of sinuous prong passages for receiving saidprongs, the material of the prongs being sufficiently resilient torestore the prongs to their normally straight condition upon Withdrawalfrom said passages, said passages extending entirely through said socketmeans and the prongs being of sufficient length to project beyond thesocket means to enter a standard socket, and means for securing saidsocket means on a. standard socket with said passages registering withthe prong openings of the standard socket.

5. In a connector for electric wiring, a plug body having a plurality ofprongs extending therefrom, each consisting of a thin strip of readilyflexible material, and socket forming means having a plurality ofpassages extending from end to end thereof for receiving said prongs nand each consisting of a pair of endwise aligned end terminal portionsmerging at their inner ends into curved portions terminating in a bowedportion, the said several portions of each passage coacting to cause theflexing of a prong, intermediate its ends when inserted into thepassage, said prongs being of a length to extend from said means toenter a standard socket forming element to make electrical contact inthe latter.

6. In a Connector for electric wiring, a plug body having a plurality ofprongs extending therefrom, each consisting of a thin strip of readilyflexible material, and socket forming means having a plurality ofpassages extending from end to end thereof for receiving said prongs andeach consisting of a pair of endwise aligned end terminal portionsmerging at their inner ends into curved portions terminating in a bowedportion, the said several portions of each passage coacting to cause theflexing of a prong, intermediate its ends when 'inserted into thepassage, said prongs being of a length to extend from said means toenter a standard socket forming element to make electrical contact inthe latter, the bowed portions of said passages being oppositelydisposed.

7. In a connector for electric Wiring, a plug body having a plurality ofprongs extending therefrom, each consisting of a thin strip of readilyflexible material, and socket forming means having a plurality ofpassages extending from end to end thereof for receiving said prongs andeach including a pair of inner endwise aligned end terminal portions andan outwardly directed bowed shaped central portion, the said severalportions of each passage coacting to cause the flexing of a prong,intermediate its ends when inserted into the passage, said prongs beingof a length to extend from said means to enter a standard socket formingelement to make electrical contact in the latter.

8. In a connector for electric Wiring, a socket member for mounting on astandard socket forming element having passages extending from end toend thereof, and a plug formed with continuous contact prongs ofstrip-like form of greater length than and for extension through saidpassages and of a length to extend into said element to make electricalcontact therewith, said prongs being formed of readily flexiblematerial, said passages being formed with offset portions intermediatetheir ends to cause the flexing of the prongs, intermediate their endswhen the prongs are inserted in the passages.

9. In a connector for electric Wiring, a socket member for mounting on astandard socket forming element having passages extending from end toend thereof, and a plug formed with continuous contact prongs ofstrip-like form of greater length than and for extension through saidpassages and of a length to extend into said element to make electricalcontact therewith, said prongs being formed' of readily flexiblematerial, said passages being formed with offset portions intermediatetheir ends to cause the exing of the prongs, intermediate their endswhen the prongs are inserted in the passages, said offset portions beingoppositely disposed and directed outwardly with respect to the remainingportions of said passages. l

10. In a connector for electric wiring, a socket member for mounting ona standard socket forming element having passages extending from end toend thereof, and a plug formed with continuous contact prongs ofstrip-like form of greater length than and for extension through saidpassages and of a length to extend into said element to make electricalcontact therewith, said prongs being formed of readily flexiblemateria'l, said passages being formed With offset portions intermediatetheir ends to cause the flexing of the prongs, intermediate their endswhen the prongs are inserted in the passages, the cross section area ofsaid offset portions being such td provide for the Walls of the passagesto snugly engage the prongs.

11. In a connector for electric Wiring, a socket member for mounting ona standard socket forming element having passages extending from end toend thereof, the intake end or mouth of each passage being iiared, eachpassage being formed with endwise aligned end terminal portions and anintermediate portion offset with respect to its aligned end terminalportions, and a plug formed with continuous prongs of striplike form ofgreater length than and for extension through said passages and of alength to extend into said element to make electrical contact therewithsaid prongs formedl of normally non-flexed readily flexible material,said offset portions causing the exing of the prongs intermediate theirends when the prongs are extended through the passage.

12. In a connector for electric Wiring, a plug body having a pluralityof flexible strip-like prongs extending therefrom and a socket formingmeans having a plurality of passages extending from end to end thereoffor receiving said prongs, the configuration of said passages being suchas to bow the prongs intermediate the ends thereof said means includingan annular flange provided with openings for the passage of holdfastdevices for anchoring it in juxtaposition to a standard socket formingelement, and said prongs being of greater length than said passages andof a length to extend into and make electrical contact in said element.

` HORACE R. ELLIS.

